The Bible indicates that God is eternal and outside of time. As we understand from science, time, space, and matter all came into existence at once. The Creator of time, space, and matter must of necessity be outside of time, space, and matter. God reveals in the Scriptures that He is eternal (outside of time) and He is spirit (outside of space and matter).
Learning or growing in knowledge takes place inside of time, so, in a way, this concept is irrelevant to a Being who is outside of time.
Psalm 139 seems to indicate that God's knowledge includes what we will do in the future:
Even before a word is on my tongue, behold, O LORD, you know it
altogether. Psalm 139:4 ESV
It also indicates that God was able to see what was yet unformed, and that every one of our days was written in a book before we were born.
Your eyes saw my unformed substance; in your book were written, every
one of them, the days that were formed for me, when as yet there was
none of them. Psalm 139:16 ESV
So, a very common position is that God has always known everything. His knowledge has never grown, but has always been complete and infinite.
As one person questioned, "Has it ever occurred to you that nothing has ever occurred to God?"
This doctrine is one that provides us with exceedlingly abundant comfort, because it means that God will never be surprised at our failures. There will never be a time when God gets buyer's remorse when our sins become greater than he originally anticipated. His salvation accounts for all of our sins that we will ever commit--even sins we didn't know we would commit--from the very beginning. He drew us to Himself knowing full well how frequently and how great we would fail and continue in our sin.